If you're looking for ~500-1000 display panels with the intent to buy, I would strongly suggest speaking with an account manager, sales rep, and/or applications engineer at a distributor. Such an order will likely generate enough revenue for them to give you a whole lot more than the time of day. I know the local account managers and FAE's for a few large component distributors in my area (Future Electronics and Allied Electronics), and they are usually helpful, though not always prompt.
Looking at Future, they do seem to have a few LCDs quoted on their site, however it is certainly not a comprehensive list. If you contact a sales rep (there or anywhere) and provide them your requirements, they may come back with additional parts that their manufacturers produce that better fit your need.
Unless your volumes are going to be in the millions, let me dispel any thoughts you have of "Why not just talk to (LCD mfc) directly?". Said manufacturers will not care about you, and the premium they will charge to deal with you (if they bother at all) will be higher than what a typical distributor would, because, frankly, they do not want your direct business. Use the middlemen. They will make specifying, finding, and sourcing LCD panels vastly easier and cheaper.
